Could be as mundane as a flat tire and a dead phone battery, or could be a horrendous crime took place. Truly a wide range of possibilities with a missing person and no specification of time spent missing.

At first I was wondering what might account for the change in the relative heights of Devyn and Alexis between Panels One and Two, but I just now noticed the ponytail on the girl talking in Panel Two. This makes it reasonable to conclude that she’s actually Abbie, talking to Alexis.